An imaging lens module (1, 2, 3, 4) includes a lens element (11, 41, 51, 61) having an optical axis, a lens carrier (12, 22, 32, 42, 52, 62) and a variable through hole assembly (13, 43). The lens carrier accommodates the lens element and sequentially includes an object-side portion (121, 421, 521, 621), an image-side portion (122, 322, 422) and a tubular portion (123, 423). The object-side portion configured for light entering the imaging lens module forms a minimum opening (OP) of the lens carrier. The variable through hole assembly is disposed on the object-side portion and includes rotatable blades (132, 432) rotatably disposed about the optical axis and configured to form a through hole (TH) with a variable size. Moreover, the object-side portion further has a guiding structure (1212, 4212) guiding the movement of the rotatable blades and located further away from the optical axis than the minimum opening. Moreover, the object-side portion and the image-side portion form an air sleeve (AS) therebetween, and the air sleeve is located further away from the optical axis than the tubular portion.